After cutting pipes, they must be reamed for what purpose?

Reaming pipes after cutting is essential for ensuring that the internal diameter of the pipe is smooth and free from burrs and chips. When pipes are cut, the cutting process can leave sharp edges or uneven surfaces, which can adversely affect the flow of air or fluids through the piping system.

By reaming the inside of the pipe, any metal shavings or burrs that may restrict flow or create turbulence are removed. This results in improved serviceability and longevity of the piping system. Smooth edges also help facilitate better connections when joining pipes or fittings, reducing the risk of leaks.

Ultimately, this preparation step is crucial for proper installation and function in HVAC systems, contributing to overall efficiency and performance.